Coating of Insertable Medical Devices (IMD) with drug remains a challenge. Generally, IMD such as a stent, a balloon and, stent and balloon assembly is coated with drug particles using various methods such as atomization, dipping, Chemical Vapor Deposition (CVD), using a drug brush etc. Similar methods are used for coating balloon-catheter assemblies.
In case of atomization, a stent is fixed to a mandrel fixture and the mandrel fixture is rotated. A spray gun nozzle deposits drug particles on the rotating stent. Further, in the case of CVD, a stent is held stationary in a vapor chamber containing drug particles suspended in a vapor medium. However, in these methods, inner and outer surfaces of the stent are coated with drug particles. Thereafter, a balloon-catheter assembly is coated using any of the above-mentioned methods and then the stent is crimped to the balloon in the balloon-catheter assembly.
In scenarios where the stent is pre-crimped to a balloon-catheter assembly, generally, the CVD method is used to coat the pre-crimped stent. However, the drug particles are not uniformly deposited on the pre-crimped stent using this method.
Therefore, there is a need in the art for a method and system for efficiently coating a pre-crimped stent with drug particles. Further, there is a need in the art for methods for using a spray gun nozzle to coat a pre-crimped stent with drug particles.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.